CAIRO - Towering metal gates erected near Cairo's Tahrir Square by the army-backed authorities has drawn criticism as a new form of police repression in an area where Egyptians launched a historic uprising for democracy in 2011.Its top bristling with spikes, and painted in the national colors, the three-metre-(10-foot)-high structure was put up in what the Interior Ministry has depicted as an effort to restore a semblance of normality to central Cairo.It replaces one of the many temporary concrete walls that sprang up in the district over the past three years. It has been left open so far since it was opened on the weekend, restoring Kasr el-Eini street as a major traffic thoroughfare, but could be shut at a moment's notice."These gates were put up temporarily. In the case of any security incidents, they will shut the street," said Hany Abdel Latif, spokesman for the Interior Ministry.Critics say the fortified structure perpetuates what they hoped were only temporary blockades and reinforces the sense of a nation in crisis seven months after the army ousted elected President Mohamed Morsi of the Muslim Brotherhood."I would like to ask: does anyone know the opening times of the Kasr el-Eini crossing?" Hanan Hagag, a journalist, quipped on her Facebook page, likening the barrier to Egypt's heavily guarded border crossing with the Gaza Strip.